No, no, don't get me wrong, I'm not going to praise Blizzard's decision to release a Diablo version for mobiles. After the initial "shock" (I'm not a Diablo player myself, but I can sympathize), I started thinking that maybe - and that's a big MAYBE - this move by Blizzard can lead to a positive side-effect.
If Blizzard sees the future of its revenues in mobile gaming, that could be a chance to start treating its other games differently - being willing to take more commercial risk and thus make more daring decisions in terms of gameplay.
Retail WoW was watered-down over the years in an attempt to please everybody fast to keep subscriptions coming (despite this having the opposite effect, apparently). Securing other sources of (main) revenue might be the catalyst for a turn to more challenging gameplay design - much like the gameplay found in Vanilla WoW, where effort was rewarded and nothing was free.
It might all be wishful thinking on my part, but it's not entirely impossible either.